Communication device for a sewing machine

ABSTRACT

A communication device and method to operate a sewing machine ( 1 ) based on a bidirectional transmission of data between the sewing machine ( 1 ), on the one hand, and a radio-controlled object, in particular a foot control ( 5 ) or an allocated radio-controlled module ( 9 ) are provided. By way of mutual transmission of identification codes, an unambiguous allocation of sewing machine ( 1 ) and the respective radio-controlled objects occur. Safe and malfunction-free data transfer is permitted by the redundancy of the data transmitted

BACKGROUND

The invention relates to a communication device for a sewing machine, a foot control, as well as a method for operating a sewing machine.

Sewing machines are generally controlled via a foot control, which is connected to the sewing machine via a connecting cable. It is already known to transmit control parameters wirelessly via radio control to a receiver connected to the sewing machine. DE 102005005882 discloses such a method for a wireless control of a sewing machine. A wireless receiver module can be connected to the sewing machine in a detachable manner. A speed control module, separated from the sewing machine, and/or a foot control comprises a battery unit, a micro computer, and a transmitting unit. The control of the motor unit of the sewing machine via the speed control module occurs first via an initialization, with a safety code part of the speed control module being transmitted to the receiver module. Then the speed control module transmits the control signals according to the pedal position with an identification part and a coded speed control part to the receiver module.

One disadvantage of this arrangement is the fact that during initialization no clear allocation occurs between the foot control having the speed control module and the receiver module coupled to the sewing machine. A foot control could therefore simultaneously transmit control signals to several sewing machines. This represents a considerable safety risk.

SUMMARY

Therefore the object of the present invention is to provide a method and a device allowing a safe and unambiguous transmission of control signals of a foot control to a sewing machine.

Another object is to provide the method and the device such that not only control signals are transmitted from the foot control to the sewing machine, but that the sewing machine and any correspondingly configured additional objects can communicate and/or exchange data with each other.

These objects are attained in a communication device, a foot control, and a method for operating a sewing machine according to the invention.

According to the invention, one communication device is allocated to each of the sewing machine and the foot control, which allow a bidirectional transmission of data. The sewing machine and/or a first communication module that can be connected to the sewing machine, and the foot control and/or a second communication module that can be integrated in or connected to the foot control each comprise a transmitting and a receiving device, and/or a transceiver as well as a data processing device and a memory. In the memory of each communication module, a unique object ID is saved, which comprises a class ID specific for each device type and a unique ID unambiguously identifying the respective object. Devices and accessories with such communication modules can be connected to a wireless radio network. Here, the sewing machine is generally the host and controls the components or additional devices signing on and off, which are located in the range of the radio connection. When a foot control signs on the respective foot control ID is stored in the memory of the communication module of the sewing machine. In response thereto the sewing machine ID is stored in the memory of the communication module of the foot control. By this unambiguous allocation of device IDs and their use in the radio protocol, it is possible to prevent the possibility that one foot control can simultaneously be signed on to several sewing machines. In addition or instead of a foot control, other accessories, external computers, or additional sewing machines can be included in the network and communicate with the sewing machine in the same manner. The resistance to interference can be further increased by combining several additional independent measures, such as data redundancy, multi-channel operation, and the use of checksums.

BRIEF DESCRIPTION OF THE DRAWINGS

Using some figures the invention is explained in greater detail in the following. Shown are:

FIG. 1 a schematic view of a wireless network with several objects connected to a sewing machine,

FIG. 2 a schematic view of the wireless network comprising a sewing machine and a computer with connected communication modules and a foot control with an integrated communication module, and

FIG. 3 a processing scheme for the redundant transmission of data.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a first sewing machine 1, which is connected and/or can be connected to additional objects and/or accessories and/or devices via a wireless radio network 3 (symbolically shown by serrated double arrows). Preferably one or more globally licensed radio frequencies in the 2.4 GHz-band are used for the communication.

In the exemplary arrangement of FIG. 1 the additional objects are represented by a foot control 5, an external computer 7, and another sewing machine 1. Additionally or alternatively e.g., tambour frames, external input devices, displays, headsets with voice control, radio bracelets with manual controls, and the like can be integrated as additional objects into the network 3 (not shown). The first sewing machine 1 and one or more additional objects can be connected to a communication device via radio control. Such radio connections may transmit both control data, such as e.g., the actuating variable of the foot control 5 to control the rotation of the sewing machine as well as application data, such as e.g., programs, stitch or embroidery data between the sewing machines 1 or between the sewing machine 1 and the computer 7 or other radio-controlled objects. One communication module 9 with a transceiver 11 and/or a transmitter and a receiver as well as an antenna 12 is allocated to the sewing machine 1 and each of the objects. Such a transceiver 11 is e.g., the type nRF24L01 of the company Nordic Semiconductor. The shockBurst™ —protocol used allows a multi-channel operation with a high transmission rate and simultaneously low energy consumption.

The communication modules 9 generally comprise a separate data processing unit (not shown) and can be implemented in the sewing machine 1 and/or in the objects that can be connected to each other in the network 3. An example, here, is the foot control 5 shown in FIG. 2. Alternatively, communication modules 9 can also be connected to and/or with the sewing machine 1 and/or the objects via appropriate interfaces 13. In FIG. 2, a communication module 9 is integrated in a dongle and/or a small housing 15 with a four-pin stereo jack and connected to the sewing machine 1 via a respective stereo receptacle. Preferably the stereo plug receptacles are used as interfaces 13 for the sewing machine 1 that are provided to connect a wired foot control 5. Alternatively a RS-232-interface can also be used as an interface 13, e.g. In the computer 7, which may be integrated as another object in the network 3, the communication module 9 may also be installed in a dongle 15. It is connected and/or can be connected to the computer 7 via a USB interface 13. In case of a permanent malfunction, instead of a wireless foot control 5 a conventional foot control 5 can be directly connected to the sewing machine 1 via a cable having a connector for the socket provided for said purpose. Of course, wireless operable foot controls 5 may also be provided with an interface to connect a connection wire. If necessary, such foot controls 5 can be connected to the sewing machine 1 and be used like conventional wired foot controls 5. By connecting a cable the communication of this foot control via radio is actively prevented for safety reasons.

In the sewing machine 1 shown in FIG. 2, two processors 17 a and 17 b are connected to the communication module 9 and control the data transmission from and to the communication module 9. Both processors 17 a, 17 b are connected to a safety module 19. This module checks safety relevant data provided by the processors 17 a, 17 b. An output of the safety module 19 is connected to the drive 21 of the sewing machine 1. An output of the second processor 17 b is also connected to the drive 21 via an actuating variable wire 23.

The second processor 17 b calculates the actuating variables for the drive 21 to be emitted to the actuating variables wire 23. The calculations are made based on data delivered to the sewing machine 1 from the communication module 9 via the foot control interface 13. If instead of the communication module 9 a conventional foot control 5 is connected to the foot control interface 13 of the sewing machine 1 via a cable the actuating variables 24 delivered by this foot control 5 are processed accordingly.

Based on the data transmitted by the communication module 9 to the sewing machine 1 the first processor 17 a calculates the data or signals to be emitted to the safety module 19.

The safety module 19 controls and/or overrides the data and/or actuating variables fed to the drive 21 via the actuating variables cable 23.

In an alternative embodiment of the invention the first processor 17 a may also accept the execution of the tasks of the second processor 17 b. Thus the latter is omitted. In the same manner, in other embodiments, the safety module 19 may be integrated partially or entirely in the first processor 17 a. If several processors 17 a, 17 b are provided, e.g., safety-relevant data can be processed redundantly, thus safety can be increased. In such a data redundancy, e.g., the control of the drive 21 of the sewing machine 1 with an actuating variable other than zero can be controlled depending on the calculations of the two processors 17 a, 17 b delivering a release signal for the safety module 19 independent from each other. Of course, it is also possible to have the parameters themselves be calculated redundantly by two processors.

In sewing machines 1 having a USB-interface 13, the communication device, e.g., a communication module 9 that can be connected to the USB-interface 13, may comprise an additional cable to connect it to a 2-pin foot control socket of the sewing machine 1 (not shown).

In sewing machines 1 comprising merely a 2-pin foot control socket and no USB-interface 13, e.g., a communication module 9 with an integrated battery 25 and a switch for activation and/or termination of the sleep mode can be used, embodied as dongle 15, which can be connected to said foot control socket, in order to allow a wireless communication to the foot control 5 (not shown.)

In addition to the integrated or installed radio and/or communication module 9, the foot control 5 shown in FIG. 2 comprises a processor 17 c and an electric energy storage, for example a battery 25. Preferably the battery 25 is a lithium battery with high energy density and low self-discharge rate. The processor 17 c evaluates the pedal position of the foot control 5, which e.g., can be determined via an integrated potentiometer or rotary encoder. Furthermore, the processor 17 c is also used to control the data transfer passing through the communication module 9. Therefore, no additional processor is necessary for this task in the communication module 9.

Each communication module 9 comprises a memory 27 or has access to a memory 27. An identification code is saved in the memory 21 precisely allocated to the respective communication module 9 and/or the respective object allocated to the memory 27. The identification code, in the following called object ID 29, comprises a class ID 31, specifying the device type and/or the type of device (e.g., host radio dongle for certain sewing machine families), having e.g., a length of 16-bit and an unambiguously identifying Unique-ID 33 for the respective object (e.g., production date and time, together measuring e.g., a length of 32-bit.)

The memory 27 can alternatively also be integrated in the sewing machine 1 or other objects (not shown) that can be integrated in the network 3. In this case, the identification code is in an unambiguous relationship to the respective sewing machine 1 and/or the respective other object. In such a configuration an exchange of communications modules 9 is possible, that can be connected externally to interfaces 13 of sewing machines 1 or additional objects, as long as they have compatible interfaces 13.

In order for a radio controlled object to be integrated into a network 3 it first must be signed on there. In the following, the sign on procedure, operation, and sign off procedure of a foot control 5 is explained for a sewing machine 1, serving as the host. It shall not be possible for the foot control 5, being the peripheral, to be signed on to several sewing machines 1 simultaneously. After the battery 25 has been inserted, the communication module 9 allocated to the foot control 5 periodically transmits data packets with its object ID 29, a status information 30, which provides information regarding the perhaps already made allocation to a host (e.g., a status bit or the object ID 29 of said host), and any additional data such as e.g., the actuating variable 24 representing the pedal position of the foot control 5, a serial number, and a checksum (CRC).

Of course, the data packets may also comprise additional or other information, such as the charge status of the battery 25 or the execution of a reverse kick at the foot control 5.

Here, the sewing machine 1 executes a scanning process, detects all peripheral devices located within range (approximately 50 m in open areas, approximately 15 m in buildings; may be reduced for foot controls 5 to approximately 1.5 m) by reduced transmission power and lists them together with the respective object ID 29 and the respective status 30 on a display at the sewing machine 1. In the setup program of the sewing machine 1 a foot control 5 no yet allocated can be selected. Its object ID 29 can also be listed on the label, so that the number respectively allocated to the desired foot control can be selected. The object IDs 29 may be displayed only incompletely on the display, as an additional safety measure. The missing numbers must then be added manually. A sign in can only occur with a correctly completed object ID 29. Upon a prompt from the host, the object ID 29 of the host and/or the sewing machine 1 is saved in the data storage 27 of the foot control 5. The host in turn saves the object ID 29 of the respective foot control 5. After this unambiguous allocation the foot control 5 can no longer be signed in with any other sewing machine 1.

The original status without any allocation to a host can e.g., be initiated by a short-term removal of the battery 25 or by pressing a reset button (not shown) at the foot control 5. This way, the matching can be terminated between the foot control 5 and the sewing machine 1 and/or the foot control 5 can be signed off the sewing machine 1. Alternatively a matching between the foot control 5 and the sewing machine 1 can also be achieved in the setup program of the sewing machine 1 by completely pressing down the foot control 5 within a predetermined period of 5 s, for example.

After the foot control 5 has been idle for an extended period of time, e.g., 5, 10, or 15 minutes, it may switch to an energy savings mode in an appropriate configuration and e.g., by reset into the operating mode by a single complete pressing of the pedal.

FIG. 3 shows a potential process for data transmission from the foot control 5 to the sewing machine 1. Any transmission only occurs in a pedal position outside the idle or zero position. Otherwise no signals are transmitted by the foot control 5. Then, the foot control 5 is in the energy saving mode and only monitors the setting of the foot control.

In FIG. 3, the time bar arranged at the left shows the progression of time t. Here, two redundant data packets each with the object ID 29 of the communication module 9 allocated to the foot control 5, the respective actuating variable 24, a status information 30, and a checksum CRC are transmitted periodically with a period Δ1+Δ2 via two frequency channels CH1 and CH2 at a temporal interval Δt1 of 50 ms, for example. Instead of two, several redundant data packets may also be transmitted. It is also possible to transmit the actuating variable 24 inside each data packet several times. By such data redundancies the safety of the transmission can be additionally increased. Faulty data packets or data packets originating from other transmitters are not permitted for evaluation.

In another variant the frequency channel CH1, CH2 are changed only when a malfunction is detected. This can e.g., be the case when n of m of the data packets received by the sewing machines 1 are faulty, with n≦m and with n and m being natural numbers. The change of the frequency channel CH1, CH2 can either be initiated automatically or by operation of a switch at a sewing machine 1 or at the foot control 5. In case of a detected malfunction the motor control can be switched off, for example, and thus the braking action may be initiated.

In case the malfunction or interruption of the radio connection extends for a longer period of time (longer than 300 ms, for example) or if successive n data packets are not identified, an emergency stop of the motor of the sewing machine can be triggered. An emergency stop may also be initiated when the foot control 5 and/or its communication module 9 is not operated for an extended period of time. The emergency stop condition may be indicated e.g., via an additional information at the display of the sewing machine 1 and/or via a briefly sounding alarm. In this case the drive 21 of the sewing machine may be restarted, for example, by a key at the sewing machine 1 being operated.

Using the communication device according to the invention, e.g., several sewing machines 1 can be configured by a computer 7 via radio. Both in the production of sewing machines 1 as well as the instruction of groups comprising several participants and sewing machines 1, several sewing machines 1 can therefore be efficiently configured. In these cases the computer 7 serves as the host. This may be detected e.g., by a hierarchic order of the class IDs 31 among the participants in a network 3, with the class ID 31 of the computer 7 ranking higher in the hierarchy than those of the sewing machine 1. In case of several participants within a single class in turn prioritization can be set according to the unique IDs 33.

In a particularly beneficial embodiment, the computer 7 may allocate a common group ID to several sewing machines 1, which then are used instead or in addition to the unique object ID during the communication with these sewing machines 1. This way several sewing machines 1 can simultaneously be addressed by the higher ranked computer 7. This can be beneficial, e.g., when in a class room or in a production facility for sewing machines 1, and several sewing machines 1 must be configured approximately simultaneously, or when e.g., a demonstration video shall be transmitted as simultaneous as possible to several sewing machines 1. The application range of the communication device is expanded such that it can not only be used for the unique bidirectional communication, but (after a respective configuration) also to a unidirectional data transmission or bidirectional communication between a computer 7 and several sewing machines 1.

Preferably, it can be determined at the sewing machine 1 in a basic configuration of the sewing machine 1, e.g., by switching a status bit on or off, if the machine is determined for a home application with only one foot control 5 here, or for the use in a class room with the simultaneous presence of several sewing machines 1 and several foot controls 5. Then, depending on the setting of this status bit, different menu options can be presented for selection (e.g., option to select one of several detected foot controls) and/or different functions can be executed.

Similar to sewing machines 1, foot controls 5 or other objects may also be embodied such that they can be addressed and configured simultaneously by a computer 7. Here, too, preferably a status bit may predetermine the purpose for use (home use or training facility). Parameters configured in this manner are e.g., the transmission curve between the respective pedal position and the allocated purpose for use of the foot control (e.g., control of the sewing speed or the on-off switch for freehand quilting). Particularly in home applications, a configuration of the foot control 5 may also be provided by the respectively allocated sewing machine 1. A purely wired foot control 5 may also be embodied in a configurable manner.

The charge status of the battery 25 in the foot control 5 can be monitored e.g., such that the foot control 5 periodically or according to predetermined rules transmits marker bits to the sewing machine 1. The sewing machine 1 confirms the receipt of such marker bits by transmitting a confirmation note to the foot control 5. When the battery charge is too low the transmission power is to low as well, to ensure a safe data transmission from the foot control 5 to the sewing machine 1. Thus, individual or several confirmation signals of the sewing machine 1 are omitted. When the foot control 5 detects the lack of n of m confirmation signals it can indicate the insufficient charge of the battery 25 by an acoustic and/or optic signal. In order to prevent any sudden interruption of the communication between the foot control 5 and the sewing machine 1 it may be provided, e.g., that the foot control 5 sends with a reduced transmission power when the battery charge is sufficient, and after a battery charge being determined too low with an in general increased transmission power. Instead of a marker bit, the receipt of data can also be monitored by the sewing machine 1.

List of Reference Characters

-   1) Sewing machine -   3) Network -   5) Foot control -   7) Computer -   9) Communication module -   11) Transceiver -   12) Antenna -   13) Interfaces -   15) Small housing -   17 a, b, c) Processors -   19) Safety module -   21) Drive -   23) Actuating variable cable -   24) Actuating variable -   25) Battery -   27) Memory -   29) Object ID -   30) Status information -   31) Class ID -   33) Unique ID 

1. A communication device for a sewing machine (1), comprising a first communication module (9) being arranged in or at the sewing machine (1) for a wireless transmission of data from another communication module (9) to the first communication module (9), the communication modules (9) each comprise a transmission and a receiving device for bidirectional data transmission.
 2. A communication device according to claim 1, wherein the at least two communication modules (9) can be connected to a network (3).
 3. A communication device according to claim 1, wherein each of the communication modules (9) comprises a memory (27) or is connected or can be connected to a memory (27) and an identification code is saved in the memory (27).
 4. A communication device according to claim 3, wherein the identification code is in an unambiguous relationship to a respective one of the respective communication modules (9).
 5. A communication device according to claim 1, wherein each of the communication modules (9) comprises a memory (27) to save identification codes of additional communication modules (9).
 6. A communication device according to claim 5, wherein the additional communication module (9) is provided in or connected to at least one of: a) a foot control (5), b) another accessory of the sewing machine (1), c) another sewing machine (1), or d) an external computer (7).
 7. The communication device according to claim 1, further comprising a foot control (5) with a communication module (9).
 8. The device according to claim 7, further comprising a connection cable or an interface for a connection cable to make a connection to the connection interface for a cable-connected foot control (5) to the sewing machine (1).
 9. A method for operating a sewing machine (1) with a communication device, comprising signing on a radio-controlled object to the sewing machine (1) or a communication module (9) allocated to the sewing machine (1), and transmitting and saving with mutual identification codes.
 10. A method according to claim 9, further comprising transmitting data packets from the radio-controlled object to the communication module (9) of the sewing machine (1), with the data packets comprising information regarding a sign in status of the radio-controlled object.
 11. A method according to claim 10, wherein the radio object is a foot control (5) or a communication module (9) allocated to a foot control (5), and data packets are transmitted depending on a position of a pedal of the foot control (5) and the data packets comprise an actuating variable according to a respective position of the pedal.
 12. A method according to claim 11, wherein at least one of the data packets or the actuating variables are transmitted redundantly.
 13. A method according to claim 10, wherein the radio-controlled object comprises a battery (25) and the method further comprising detecting missing confirmation signals by the sewing machine (1) to monitor a charge status of the battery (25). 